How do you pick the right diesel engine model? This is a challenging task. You’ll need plenty of information if you’re deciding between the Caterpillar 3406E, C15 ACERT, or C15 engine. And we have as much information as you can get to make an informed decision.
Learn the Good and Bad About These Iconic Caterpillar Engines.
The last thing you want is to spend your hard-earned money on an unreliable engine! We’ll cover everything you need to know about these engines: what sets them apart, their unique problems, and any important specifications.
Looking to upgrade your engine? Talk to Our ASE Certified Technicians!
Caterpillar 3406E
The Caterpillar 3406E has a longstanding reputation for being a reliable engine. Many mechanics praise it as one of the best. The 3406E has been well-loved since it first began production in 1993. It’s also the first diesel motor with fully electronic monitoring systems giving it a rare advantage over all other engines, even those in the same series.
Caterpillar released many variations of the 3406, including the 3406A, 3406B, 3406C, and finally the 3406E. The 3406A/3406B engines were both fully mechanical. The C model version was mostly mechanical, except for its fuel pump. Eventually, the 3406E was the first diesel motor with all electronic monitoring, fuel injection, and more. It worked so well, that this engine type is still being used today. Our Caterpillar 3406E Engine Spotlight highlights some of the history, serial numbers, and aftermarket improvements to the model.
Common Caterpillar 3406E Problems
In terms of design, the Caterpillar 3406E is an excellent design. It’s not without a few minor issues, however.
Oil leaks are sometimes an issue for the 3406E, with the most common leaks occurring near the rear side of the engine, around the spacer plate and cylinder block. During its production, Caterpillar wasn’t using the best gaskets for the 3406E. This issue was present in early production models but was eventually fixed in later versions. Sometimes the rubber plugs in the back of the engine block hardened as they age and are introduced to extreme heat and other elements, which caused oil leaks.
You should consider the age of your engine. Back in the day, 3406E engines were thought of as nearly unbeatable. As these engines age, they will be more prone to oil leaks.
Caterpillar 3406E Engine Specifications
- Fuel: Diesel
- Liter: 14.6
- Cubic Inch Displacement: 893
- Cylinder Bore Diameter: 5.4000-5.4020″ (137.16-137.211 MM)
- Stroke: 6.500″ (165.1 MM)
- Cylinder Configuration: L6
- Engine Comments: 3406E truck, OHC, 24-valve
Caterpillar C15
Following the production of the 3406E, Caterpillar released the C15 in 1999. This engine is very popular because of its reliability and versatility. It’s so versatile in fact, that Cat lists over 34 applications that are powered by this engine. These include combines, harvesters, paving equipment, pumps, earth-moving equipment, aircraft support, and many more.
This design was meant to improve on the previous 3406E model. These improvements included gasket upgrades and better seals to fix those leaks we mentioned before. If you’re in the market, we have a wide range of high-quality parts for the C15 available. You can also find more information on the history, aftermarket improvements, and serial numbers in our C15 Engine Spotlight blog.
Does Cat Still Make The C15?
No, Caterpillar stopped production of the C15 in 2010. But the good news is that engine rebuild kits for C15 engines are currently available to renew this diesel juggernaut. However, it will increase build time due to availability.
Common Caterpillar C15 Problems
To improve upon the 3406E diesel engine, Caterpillar introduced relief slots on the cylinder head to prevent pressure on the gaskets. Unfortunately, after the addition of these slots, the gaskets were known to fail a bit more often.
To solve this, make sure you’re buying high-quality C15 gaskets built to strict OEM specifications, giving you proper fit and function.
You won’t hear many good things about the C15’s MBN prefix. Caterpillar faced another problem when they released the MBN model between 2002-2003. This model garnered the nickname “Much Bad News,” and for good reason. They ran at high temperatures, guzzled fuel, and couldn’t pull very well.
Is the Cat C15 A Good Motor?
The Caterpillar C15 is a popular engine known for being good and reliable. Even though production stopped in 2010 there are still several out on the road so the need for new parts like C15 fuel injectors, cylinder heads, rebuild kits, and more is still great.
Caterpillar C15 Engine Specifications
- Fuel: Diesel
- Liter: 15.2
- Cubic Inch Displacement: 928
- Cylinder Bore Diameter: 5.4000-5.4020″ (137.160-137.210 MM)
- Stroke: 6.732″ (171.000 MM)
- Cylinder Configuration: L6
- Engine Comments: Diesel SOHC Electronic, Similar To 3406E, Non-ACERT
Caterpillar C15 ACERT
In 2004, The Caterpillar C15 shifted to the C15 ACERT: Advance Combustion Emission Reduction Technology. This upgrade revamped the engine’s air and fuel systems to meet stricter EPA emission requirements, enacted in 2002.
Some people believe the only difference between the C15 and the C15 Acert is that the C15 is a single turbo, while the C15 ACERT is a dual turbo. Though quality turbochargers for the C15 Acert are vitally important, there’s more to the ACERT than just the number of turbos they have. One feature that Caterpillar improved upon was the piston design. The regular C15 has a two-piece aluminum skirt piston, while the ACERT has a one-piece steel design, making it much stronger.
Caterpillar C15 ACERT Problems
When tuned correctly, the C15 ACERT can be a strong, reliable engine. Despite its potential, the earlier versions of this engine still ran into technical issues.
At the beginning of C15 ACERT production, broken rocker studs were common. Now, most ACERTs use updated studs to solve that problem. The exhaust manifolds had issues with their studs often breaking, as well.
Age and fuel mileage will take a toll on the C15 Acerts injectors. They will eventually fail without proper maintenance and replacement as needed. Simply keeping your C15 ACERT well-maintained is vital for its performance.
For more information on engine maintenance, check out our previous blog on Preventive Maintenance Inspections.
Caterpillar C15 ACERT Engine Specifications
- Fuel: Diesel
- Liter: 15.2
- Cubic Inch Displacement: 928
- Cylinder Bore Diameter: 5.4000-5.4020″ (137.160-137.210 MM)
- Stroke: 6.732″ (171.000 MM)
- Cylinder Configuration: L6
- Engine Comments: Diesel SOHC Electronic, Similar To 3406E, ACERT
Still considering which engine is the best for you? Our ASE Certified Technicians can help you find the perfect match! Give us a call at 844-304-7688, or request a quote online!
Difference Between 3406E, C15, and C15 Acert FAQs
Q. What are the main differences between the Caterpillar 3406E, C15, and C15 ACERT engines?
A. The Caterpillar 3406E, C15, and C15 ACERT share a similar foundation but have key differences. The 3406E was the first electronic version, the C15 refined its design for better reliability, and the C15 ACERT introduced Advanced Combustion Emissions Reduction Technology (ACERT) to meet stricter emissions regulations.
Q. Which engine is more reliable: the 3406E, C15, or C15 ACERT?
A. The 3406E and early C15 models are often regarded as more reliable due to their simpler design and lack of emissions components. The C15 ACERT, while still durable, includes additional emissions control systems that can lead to more maintenance requirements.
Q. Does the C15 ACERT engine have more horsepower than the older models?
A. All three engines offer similar horsepower ranges, but the C15 ACERT was designed with twin turbochargers to improve performance while meeting emissions standards. However, tuning and modifications can affect horsepower across all models.
Q. What are the emissions differences between these engines?
A. The 3406E and early C15 models were built before strict emissions regulations, whereas the C15 ACERT includes EGR (Exhaust Gas Recirculation) and twin turbos to reduce emissions and comply with EPA standards.
Q. Which Caterpillar engine is best for my needs?
A. If you prioritize simplicity and ease of maintenance, the 3406E or early C15 models might be best. If you need an engine that complies with modern emissions regulations, the C15 ACERT is a better choice.
